Booming northern orcas devouring chinook salmon that sustain southern resident killer whales

Killer whales native to the waters of northern B.C. and Alaska are selectively eating millions of large, nutritious chinook salmon long before the fish make their way to the feeding grounds frequented by our dwindling southern resident killer whales, according to new research.

Conservation efforts aimed at both killer whales and chinook salmon may be having “unexpected consequences,” said the study’s lead author Jan Ohlberger, from the University of Washington’s School of Aquatic and Fishery Sciences.

The problem is that booming populations of northern resident killer whales and Alaska residents are getting first crack at the best chinooks, those more than 76 centimetres (30 inches) long.

Unlike the southern resident group which is hovering at about 73 individuals, there are 300 northern residents and 2,300 Alaska residents, about three times as many as 30 years ago.

https://vancouversun.com/news/local-news/booming-northern-orcas-devouring-chinook-salmon-that-sustain-southern-resident-killer-whales